commit 27f39c73e63833b4c081a0d681d88b4184a0491d
author Eric Dumazet <eric.dumazet@gmail.com> Wed May 19 22:07:23 2010 +0000
committer David S. Miller <davem@davemloft.net> Mon May 31 00:24:01 2010 -0700
tree 49cca2881bcd9212cd99a1e30c83f40a20eefc55
parent 604c1b1868f16e7b2fc13401d8c9147f167bec0a

net: Use __this_cpu_inc() in fast path

This patch saves 224 bytes of text on my machine.

__this_cpu_inc() generates a single instruction, using no scratch
registers :

  65 ff 04 25 a8 30 01 00      incl   %gs:0x130a8

instead of :

  48 c7 c2 80 30 01 00         mov    $0x13080,%rdx
  65 48 8b 04 25 88 ea 00 00   mov    %gs:0xea88,%rax
  83 44 10 28 01               addl   $0x1,0x28(%rax,%rdx,1)

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/route.c

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 560acc6..8495bce 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -253,8 +253,7 @@
 static unsigned int		rt_hash_log  __read_mostly;
 
 static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
-#define RT_CACHE_STAT_INC(field) \
-	(__raw_get_cpu_var(rt_cache_stat).field++)
+#define RT_CACHE_STAT_INC(field) __this_cpu_inc(rt_cache_stat.field)
 
 static inline unsigned int rt_hash(__be32 daddr, __be32 saddr, int idx,
 				   int genid)